<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>

    <div id="app">
        <p>{{message}}</p>
        <input v-model="message">
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script>
        new Vue({
            el: "#app",         // id为app的元素
            data: {
                message: 'Hello Vue.js!'
            }
        })
    </script>
</body>
</html>